There is a long felt need in the manufacturing arts to develop a method for certifying that a given manufacturing facility is capable of producing a quality manufactured part of a particular type. One known means for certifying comprises defining a quality management standard, auditing the manufacturing facility against the standard and then issuing a “certificate of compliance” if the manufacturing facility meets every element of the standard.
An example of a quality management standard is ISO 9000. This is a standard requiring that a quality management program with specific elements be in place. An example of an element of this standard is ISO 9000-2 4.9 This element is summarized by Praxiom Research Limited of Alberta Canada to read in part, “All products (and services) are created by means of processes”. (source: “ISO 9000-2 Guidelines Translated into Plain English”, http://www.connect.ab.ca/˜praxiom/9000-2.htm) In other words, in order to pass an ISO 9000 audit and receive a certificate of compliance, a manufacturing facility must at least produce all products and services by a predefined process. The standard does not say what the process is or how to determine if the process is suitable for the product being produced. Nor does it give an indication that a process has acceptable yields. It merely states that the process is defined. A certification to a quality management standard, therefore, does not give a third party any indication that the manufacturing facility in question is using appropriate processes for the product being produced.
An alternative method for certifying that a manufacturing facility is capable of producing a quality manufactured product comprises auditing the products produced by a manufacturing facility to a performance specification. The Defense Supply Center, Columbus (DSCC) performs such a certification. The method for attaining the certification is described in “Qualified Products List, Qualified Manufacturers List: General Qualification Information”, published by DSCC, September 1998, pp 4–14. A generic test product and associated performance specification are defined for a given class of products, such as hybrid microcircuits. The performance specification for hybrid microcircuits is described in “Hybrid Microcircuits, General Specification for”, MIL-PRF-38534E, 6 Jan. 2003. The manufacturing facility then produces a set of the test products. The set of test products are audited or tested against the performance specification. If the parts meet all of the requirements of the performance specification, then the manufacturing facility is issued a certification to produce parts of the general class. The DSCC also additionally requires the manufacturing facility to meet a quality management standard similar to ISO 9000.
A given class of products, however, cannot be audited against a performance specification if the diversity of the members of the class is too great, or the evolution of the members of the class is too rapid. It is not possible in this situation to define a generic test product. Printed circuit assemblies, for example, are a given class of products that are too diverse and are evolving too rapidly for there to be a generic test product. The size of printed circuit assemblies can range from less than 1 mm×1 mm to more than 500 mm×500 mm. Solder joints on printed circuit assemblies can be through-hole, surface mount, and/or area arrays such as BGA or flip-chip. There is a wide array of fluxes, solder pastes, and solder alloys used to produce printed circuit assemblies. The assemblies themselves can range from disposable electronic smart cards to multimillion-dollar mainframe motherboards. Furthermore printed circuit assemblies are evolving rapidly. Solder paste formulations, component lead configurations, component pitch, lead surface metallizations and other physical parameters of the components and assemblies themselves are changing on a yearly and sometimes monthly basis. For reasons of diversity and rapid evolution, therefore, neither the DSCC nor any other entity known to the inventor has been able to define a generic test product for printed circuit assemblies and hence have not been able to certify a manufacturing facility to produce quality printed circuit assemblies to a product standard.